Fuel pressure at idle and WOT

[orrum]

Handcannon and all my diesel mentors.....Look on todays posts for a thread titled "Heath cold air intake" a guy named Ace talks about the old body style GM trucks having a factory cold air ram, my question is my truck the old body style and if so do I have a cold air ram? This is VERY inreresting!

 

[Burning oil]

Only 6.5s got a factory turbo starting in 1992. 6.5 mechanical ip's were 92-93 only from factory. My truck is a 96 that I converted to a DB2 4911 mechanical IP. IMO the 4L80E is the best transmission aside from the Allison behind the Dmax trucks. An Allison will bolt up to a 6.5/6.2 but you would have to be able to control it. Im not sure how far back the 4L80E went in a stock truck.
I would not run WVO with a DS4 ip. The optic senson can have a problem seeing through it.

 

[Burning oil]

I was typing when you posted your last.
The cold air intake is for the turbo trucks. Your truck is the old old old old body style. Easier to refer to it as a GMT400

 

[orrum]

Thanks Leroy so Mike needs a 1991 6.2 or a 92-93 6.5 turbo. I think he would like the turbo, he use to race chainsaws, seriously u oughta see a chainsaw race! LOL Fastest to cut thru a log, they r amazing chainsaws! Cool thanks a bunch but I am so dissapointed to find out I dont have a factory cold air ram :-( But I do got a heck of a GMC 6.2! I also have 21 big beautiful round bales of hay that my truck is going to haul home, about 800 lbs each and my trailer holds six so gonna find out how she tows for sure tomoro afternoon, lets see 6 bales b about 5000 lbs plus the flatbed trailer. Should tell me how a loaded horse trailer is gonna do.

 

[handcannon]

Bill

Here's the pics of the filters on my 83 6.2.

1--This filter has the air bleed and is bolted directly to the firewall. In a stock system it is set up before the mechanical fuel pump. Somebody prior to me bypassed the stock pump and added a 90s era electric lift pump so this filter is now after the LP.

2--this filter is the one that was origionally bolted on to theback of the intake manifold. In a stock system it goes between the mechanical fuel pump and the injection pump. I swapped out the stock EGR intake manifold for a military non-egr manifold. The military manifold does not have a place for this filter so I fabbed a mount to hold it. In this configuration it is still just prior to the IP. By the way, just to answer questions before they are asked, the clear lines between the filters is because I have air infiltration problems somewhere between the LP and the IP which I have never really been able to pinpoint. Once I bleed off the air, manually operating the electric LP, and start it first thing in the morning it will start easily the rest of the day as long as it doesn't set for several hours between starts.

3--This is just a better view of the two filters.

4--A different view of the filters.

Just for grins I added two pics of the air intake system the way I modified it since you just went through modifying your system. The 90s body style would not be easy to pick up intake air this way as the battery is in the way. It could be done if the battery was relocated. But you got yours done much easier.

5--This is the modified air filter canister. I took the origional base, added a taller side to it and reused the origional top. I then added two 4" snorkles and put 4" flex tube down to the radiator core support.

6--This shows the stock location for the 6.2 air intake on the core support.

I hope these pics of the filters are useful when you go junk yard hopping looking for fuel filters. It will be a long shot to find either of these, but if you do I think they will be easy to add into your system. The replacement filters are readily available at most any auto parts store.

 

[orrum]

Thanks Handcannon 4 the pics! I like ur filter setup, easy and fast to spin a new one on! Thats critical for wvo cause u never know when its gonna go on ya (on ur way to a date) or where its gonna shut down (on a bridge) yes I have put one on the Mercedes blocking traffic on a bridge! Hey I got it down to less than 4 minutes when I first started wvo and the wvo was cleaning my tank and lines! LOL U all r gonna find out cause biodiesel is like gasohol, its comin n when the biodiesel blends r all thats out there to buy Wix filters and the other filter companys will be good stock to own! Handcannon Leroy said my beautiful Gmc 6.2 was old old old old old! Now I just dont know how to take that, here I thought he liked her classic beauty, grace and elegance!!!!! LOL

 

[orrum]

Hey Buddy, Great White, Leroy and Handcannon and the rest of u diesel people I got the OPS relay mod and LP momentary switch primer mod done today!!!! Of course the OPS started acting up with wierd jumps and pegging the needle this morning before I started the mods but the mods calmed the problem down. Oil pressure needle still pegs itself occasionally.....only very seldom now. It all works great, thank ya"ll!!!! Oh yea cost was zero, had relay in truck from previous owner not hooked to anything and took the momentary button out of the Mercedes where it was not used either so I feel good about all this!!!! Got pics for ya'll too!!!

 

[orrum]

Good morning my friends!!!! Well the truck did great on my camping horse trailride but I wanna get back to my mods now with yalls help. Got a question about IPs. What IP is my truck supposed to have and is there a better db2 that I should get when my current one goes bad??? Also what kind of price is there on rebuilding a IP???? Should I be looking for a core now and get it rebuilt as a spare???? Going to get the correct stuff exchanged @ fastenol today to install my fuel pressure gauge.....finnally!!!! Been half way installed 4 a while now. Found a thread that had a list of stanadyne IPs and trucks that matched up but reading other threads it looks like u guys mix and match them.

 

[orrum]

Hey here is a pic of my gooseneck ball plate hitch that I put in the bed of the GMC. I welded it up from scraps I dug out of the recycle pile @ a friends shop and used the heavyest weight ball that Tractor Supply sold. Cost about $20 for the ball and I gave Thomas $20 to cover welding rods and gas 4 the torch. I did not have to cut anything, only drill a hole in the plate for the grade 8 half inch bolts thru the plate and the frame. Used the torch to cut holes thru the round piece and the big rectangle and put the ball post thru and cut it off flush with the bottom plate and welded the underneath side of the ball and on top the round piece of steel and the ball itself. My welding was very ugly but Thomas said it would probably have held but he welded overtop of mine to be safe and pretty it up. Used a bunch of half inch washers on the grade 8 bolt as spacers between the bed and frame and between the plate and the bed, bolt holes worked out to be in the dip in the bed. The metal plate was really pitted so my paint job came out looking pebbly but its rustoleum so maybe it will hold up. I forgot to get d-rings for the saftey chains so I cut two horseshoes down and got Thomas to weld them on for the that instead. Centered the ball 1.5 inchs in front of the center of the axle. That is Gore horse trailers reccomendation 4 a 8 foot bed, short bed they use half inch due to trailers hiting cab and knocking glass out, even then some truck and trailer combos need an extension to get the trailer far enough back. The grade 8 bolts with lock washers and nuts and grade 5 washers were $30. The rustoleum $10. This is a total of $80. U can buy the plate with ball already attached for about $180.00 with tax @ Tractor supply, u still have to paint it, drill holes, get bolts and washers so I saved about $140. I am pleased, need to retorque bolts now that I have used it a few times and then gonna weld the nuts.

 

[Koots]

Good morning my friends!!!! Well the truck did great on my camping horse trailride but I wanna get back to my mods now with yalls help. Got a question about IPs. What IP is my truck supposed to have and is there a better db2 that I should get when my current one goes bad??? Also what kind of price is there on rebuilding a IP???? Should I be looking for a core now and get it rebuilt as a spare???? Going to get the correct stuff exchanged @ fastenol today to install my fuel pressure gauge.....finnally!!!! Been half way installed 4 a while now. Found a thread that had a list of stanadyne IPs and trucks that matched up but reading other threads it looks like u guys mix and match them.

I bought a DB2831-5079 pump, which moves more fuel and has the potential for more power than the DB2829 pumps that came with our older trucks. The DB2831 pumps were built for the 6.5TD and the 4911 pump (DB2831-4911) is the most sought after. I bought a cheap used one, bought a gasket/seal refresh kit and i'm the process of installing that pump now. You would need to turn the pump down a little if you are non-turbo, i'm gonna go ahead and just move it down 1/8 turn as i will still enjoy some extra fuel

I've got a long trip with some big hills planned and my lifted 6.2 needs all the help she can get climbing hills

 

[orrum]

Hey thanks Koot.

 

[orrum]

Ahhh Hah I get to reply now cause I got my fuel pressure gauge installed today! I have a Glowshift electric gauge in my 1991 3500 GMC 6.2 N/A automatic 4L80E auto dually single cab. I have the factory square filter and factory electric fuel LP. I got 6 lbs @ idle in park or in gear, 5 cruisin @ 55-60 and 4 @ WOT. First time I had her @ WOT! I used a needle valve to act as a snubber and used it to fine tune my sensor so I get a nice slow steady increase or decrease in pressure and incorporated a fuel drain valve to bleed filter changes. I have a very steady needle with no shaking, vibration or jumping. I am going to write it up because its impossible to find info on any web sites that I could find. Hope it helps some folks. I added some pics.The pressure is measured pre IP.

 

[orrum]

Forgot the pics I think, will try again.

 

[orrum]

New readings with Walbro and two 5 micron fuel filters. Got 8psi at idle and 6-7 at cruising speed and 4-5 at WO

 

[buddy]

Wow, so you added another 5 micron filter? Is that a prefilter and then the stock 5 micron. Good pressure still with two restrictive filters. I am switching from a 12 micron to a 30ish micron prefilter soon. I have not had any issues with the 12 micron filter, its been on for two years too, just drain some water from time to time. Although its also much larger than the stock filter.

 

[orrum]

Hello Buddy. No I have a 30 micron prefilter. I wanted a 5 micron FFM water separator filter on the fender well to make changing filters easy with the wvo, it will send all the gunk thats stuck to the tank and lines along. I left the square stock one there but I figure It will be a really long time before I have to change it because the new FFM will catch most. Remember a 5 micron filter only catches 95 % so the second one will get a little too I hope. By the way thanks for getting me thru the primer button for the LP mod it sure made things easier to bleed all that air out. I blew the lines out and put the Walbro and prefilter on and the Wix FFM and filter on the fender whell all at the same time but ur primer mod handled it no problem!!!